<template>
  <div :class="isShow ? 'art-cmt-container-1' : 'art-cmt-container-2'">
    <!-- 评论列表 -->
    <van-list
      class="cmt-list"
      v-model="loading"
      :finished="finished"
      finished-text="已经到底啦!"
      :immediate-check="false"
      @load="onLoad"
    >
      <!-- 评论的 Item 项 -->
      <div
        class="cmt-item"
        v-for="item in cmtList"
        :key="item.com_id.toString()"
      >
        <!-- 头部区域 -->
        <div class="cmt-header">
          <!-- 头部左侧 -->
          <div class="cmt-header-left">
            <img :src="item.aut_photo" alt="" class="avatar" />
            <span class="uname">{{ item.aut_name }}</span>
          </div>
          <!-- 头部右侧 -->
          <div class="cmt-header-right">
            <van-icon
              name="like"
              size="16"
              color="red"
              v-if="item.is_liking"
              @click="delLikeCmt(item)"
            />
            <van-icon
              name="like-o"
              size="16"
              color="gray"
              v-else
              @click="addLikeCmt(item)"
            />
          </div>
        </div>
        <!-- 主体区域 -->
        <div class="cmt-body">
          {{ item.content }}
        </div>
        <!-- 尾部区域 -->
        <div class="cmt-footer">{{ item.pubdate | dateFormat }}</div>
      </div>
    </van-list>

    <!-- 底部添加评论区域 - 1 -->
    <div class="add-cmt-box van-hairline--top" v-if="isShow">
      <van-icon name="arrow-left" size="18" @click="$router.back()" />
      <div class="ipt-cmt-div" @click="showBox2">发表评论</div>
      <div class="icon-box">
        <van-badge :content="cmtCount" :max="99" >
          <van-icon name="comment-o" size="20" @click="scrollToCmtList" />
        </van-badge>
        <van-icon name="star-o" size="20" />
        <van-icon name="share-o" size="20" />
      </div>
    </div>

    <!-- 底部添加评论区域 - 2 -->
    <div class="cmt-box van-hairline--top" v-else>
      <textarea
        @blur="showBox1"
        placeholder="友善评论、理性发言、阳光心灵"
        v-model.trim="textContent"
        ref="textContentRef"
      ></textarea>
      <van-button
        type="default"
        :disabled="textContent.length === 0"
        @click="sendContent"
        >发布</van-button
      >
    </div>
  </div>
</template>

<script>
import { getCmtListAPI, addLikeCmtAPI, delLikeCmtAPI, pubCommentAPI } from '@/API/articles.js'
import { animate } from 'popmotion'
export default {
  name: 'ArtCmt',
  props: {
    artId: {
      // 可以通过数组,来定义多个可选的值类型
      type: [String, Number],
      // 必填
      require: true
    }
  },
  data () {
    return {
      cmtList: [], // 评论列表数据
      offset: null, // 偏移量
      loading: false, // 是否正在请求上拉加载的数据
      finished: false,
      isShow: true, // 控制评论框的显示
      textContent: '', // 输入的文本内容
      cmtCount: 0 // 评论总数
    }
  },
  methods: {
    // 调用获取文章详情接口
    async getCmtList () {
      const { data: res } = await getCmtListAPI(this.artId, this.offset)

      if (res.message === 'OK') {
        this.cmtList = [...this.cmtList, ...res.data.results] // 数据拼接
        this.offset = res.data.last_id
        this.loading = false // 将loading改为false
        this.cmtCount = res.data.total_count
        if (res.data.results.length === 0) {
          this.finished = true
        }
      }
      // console.log(res)
    },
    // 调用点赞评论接口
    async addLikeCmt (item) {
      const { data: res } = await addLikeCmtAPI(item.com_id)
      if (res.message === 'OK') {
        // item.is_liking = true  配合第一种方式使用
        this.$set(item, 'is_liking', true)
        this.$toast.success('点赞成功')
      }
    },
    // 调用取消点赞接口
    async delLikeCmt (item) {
      await delLikeCmtAPI(item.com_id)
      item.is_liking = false
      this.$toast.success('取消点赞')
    },
    // 上拉加载事件
    onLoad () {
      this.getCmtList()
    },
    // 点击切换成盒子2样式
    showBox2 () {
      this.isShow = false
      this.$nextTick(() => { // 该函数里的回调会等待isShow变量变换完,而且dom也渲染完才执行
        this.$refs.textContentRef.focus()
      })

      //  this.$refs.textContentRef.focus()  代码被执行,但是dom还没有渲染,所以无法获取焦点(因为dom渲染是异步的)
    },
    // 失去焦点时切换成盒子1
    showBox1 () {
      setTimeout(() => {
        this.isShow = true
        this.textContent = '' // 点击进入盒子2默认没有文字
      }, 100)
    },
    // 发送文本内容
    async sendContent () {
      // console.log(this.textContent)
      try {
        const { data: res } = await pubCommentAPI(this.artId, this.textContent)
        if (res.message === 'OK') {
          this.$toast.success('发布成功')
          // res.data.new_obj.is_liking = false // 给返还的数据添加一个属性,可以发送之后立即评论 第一种方式 在添加时本身不是响应式属性
          // 但是因为this.cmtList是响应式数据 而响应式数据操作的方法会把这个属性改变成响应式,所以可以实现实时更新
          this.cmtList.unshift(res.data.new_obj)
          this.cmtCount += 1 // 发送成功后,评论数量自动加1
        }
      } catch {
        this.$toast.fail('该文章不允许发表评论')
      }
    },
    // 点击跳转到评论区位置
    scrollToCmtList () {
      animate({
        from: window.scrollY, // 从文档最顶部已滚动的像素值
        to: document.querySelector('.article-container').offsetHeight, // 元素的高
        onUpdate: latest => window.scrollTo(0, latest) // 可以把内容滚动到指定的位置
      })
    }
  },
  created () {
    this.getCmtList()
  }

}
</script>

<style lang="less" scoped>
.cmt-list {
  padding: 10px;
  .cmt-item {
    padding: 15px 0;
    + .cmt-item {
      border-top: 1px solid #f8f8f8;
    }
    .cmt-header {
      display: flex;
      align-items: center;
      justify-content: space-between;
      .cmt-header-left {
        display: flex;
        align-items: center;
        .avatar {
          width: 40px;
          height: 40px;
          background-color: #f8f8f8;
          border-radius: 50%;
          margin-right: 15px;
        }
        .uname {
          font-size: 12px;
        }
      }
    }
    .cmt-body {
      font-size: 14px;
      line-height: 28px;
      text-indent: 2em;
      margin-top: 6px;
      word-break: break-all;
    }
    .cmt-footer {
      font-size: 12px;
      color: gray;
      margin-top: 10px;
    }
  }
}

//评论列表
// 外层容器
.art-cmt-container-1 {
  padding-bottom: 46px;
}
.art-cmt-container-2 {
  padding-bottom: 80px;
}

// 发布评论的盒子 - 1
.add-cmt-box {
  position: fixed;
  bottom: 0;
  left: 0;
  width: 100%;
  box-sizing: border-box;
  background-color: white;
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 46px;
  line-height: 46px;
  padding-left: 10px;
  .ipt-cmt-div {
    flex: 1;
    border: 1px solid #efefef;
    border-radius: 15px;
    height: 30px;
    font-size: 12px;
    line-height: 30px;
    padding-left: 15px;
    margin-left: 10px;
    background-color: #f8f8f8;
  }
  .icon-box {
    width: 40%;
    display: flex;
    justify-content: space-evenly;
    line-height: 0;
  }
}

.child {
  width: 20px;
  height: 20px;
  background: #f2f3f5;
}

// 发布评论的盒子 - 2
.cmt-box {
  position: fixed;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 80px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 12px;
  padding-left: 10px;
  box-sizing: border-box;
  background-color: white;
  textarea {
    flex: 1;
    height: 66%;
    border: 1px solid #efefef;
    background-color: #f8f8f8;
    resize: none;
    border-radius: 6px;
    padding: 5px;
  }
  .van-button {
    height: 100%;
    border: none;
  }
}
</style>
